ExecuteSQL: Use the context manager instead of calling ReleaseResultSet() manually.

This assumes gdal ≥3.7, see
https://gdal.org/en/stable/api/python/raster_api.html#osgeo.gdal.Dataset.ExecuteSQL .

1 files changed, 6 insertions, 11 deletions

diff --git a/export_mvt.py b/export_mvt.py
index 7b3137b..de4a351 100644
--- a/export_mvt.py
+++ b/export_mvt.py
@@ -186,11 +186,10 @@ def exportSourceLayer(lyr_src : ogr.Layer,
     ds_src = lyr_src.GetDataset()
     logging.debug('ExecuteSQL(%s%s)', query,
                   '' if spatialFilter is None else ', spatialFilter=' + spatialFilter.ExportToWkt())
-    lyr_src = ds_src.ExecuteSQL(query, spatialFilter=spatialFilter)
-    try:
+    with ds_src.ExecuteSQL(query, spatialFilter=spatialFilter) as lyr_src2:
         count1 = -1
-        if lyr_src.TestCapability(ogr.OLCFastFeatureCount):
-            count1 = lyr_src.GetFeatureCount(force=0)
+        if lyr_src2.TestCapability(ogr.OLCFastFeatureCount):
+            count1 = lyr_src2.GetFeatureCount(force=0)
         if count0 >= 0 and count1 >= 0:
             logging.debug('Source layer "%s" has %d features, of which %d are to be exported',
                           layername, count0, count1)
@@ -198,13 +197,13 @@ def exportSourceLayer(lyr_src : ogr.Layer,
         fieldMap = fieldMap[1]
         logging.debug('Field map: %s', str(fieldMap))
 
-        geom_type = lyr_src.GetGeomType()
+        geom_type = lyr_src2.GetGeomType()
         bFlatten = geom_type == ogr.wkbUnknown or ogr.GT_HasM(geom_type) or ogr.GT_HasZ(geom_type)
         bTransform = bFlatten or ct is not None
 
         feature_count = 0
         defn_dst = lyr_dst.GetLayerDefn()
-        feature = lyr_src.GetNextFeature()
+        feature = lyr_src2.GetNextFeature()
         while feature is not None:
             feature2 = ogr.Feature(defn_dst)
             feature2.SetFromWithMap(feature, False, fieldMap)
@@ -219,14 +218,10 @@ def exportSourceLayer(lyr_src : ogr.Layer,
             if lyr_dst.CreateFeature(feature2) != ogr.OGRERR_NONE:
                 raise RuntimeError(f'Could not transfer source feature #{feature.GetFID()}')
             feature_count += 1
-            feature = lyr_src.GetNextFeature()
+            feature = lyr_src2.GetNextFeature()
 
         logging.info('Exported %d features to MVT layer "%s" from "%s"',
                      feature_count, lyr_dst.GetName(), layername)
-
-    finally:
-        ds_src.ReleaseResultSet(lyr_src)
-        lyr_src = None
     return feature_count
 
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